[UncleEntity]

Pre-modern cars have something to mitigate this, testing your brakes more than a single pedal push before you go out on the road. Kind of sounds like you didn't even bother to bleed the lines which is also asking for a heap of trouble even if you managed to properly repair the entire braking system.

I've worked on the brakes on multiple cars and never once took one out for a test drive without triple-checking that I didn't make some stupid mistake that would put other people in danger.

Don't get me wrong, I had a couple cars with dodgy brakes over the years but always made sure they were good enough at the time I was driving them -- had this '53 Dodge that I had to bleed the brakes every time I wanted to take it out for a spin because the wheel cylinders were pitted and slowly leaked but always made sure to do a proper job because other people's lives were at risk too.